/****************************************************************************
 *
 * Copyright 2017 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * arch/arm/src/tiva/tiva_serial.c
 *
 *   Copyright (C) 2009-2010, 2012-2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <semaphore.h>
#include <string.h>
#include <errno.h>
#include <debug.h>

#include <tinyara/irq.h>
#include <tinyara/arch.h>
#include <tinyara/serial/serial.h>

#include <arch/serial.h>
#include <arch/board/board.h>

#include "chip.h"
#include "up_arch.h"
#include "up_internal.h"

#include "tiva_lowputc.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Some sanity checks *******************************************************/

/* Is there a UART enabled? */

#if !defined(CONFIG_TIVA_UART0) && !defined(CONFIG_TIVA_UART1) && !defined(CONFIG_TIVA_UART2) && \
	!defined(CONFIG_TIVA_UART3) && !defined(CONFIG_TIVA_UART4) && !defined(CONFIG_TIVA_UART5) && \
	!defined(CONFIG_TIVA_UART6) && !defined(CONFIG_TIVA_UART7)
#error "No UARTs enabled"
#endif

/* If we are not using the serial driver for the console, then we
 * still must provide some minimal implementation of up_putc.
 */

#ifdef USE_SERIALDRIVER

/* Which UART with be tty0/console and which tty1-7?  The console will always
 * be ttyS0.  If there is no console then will use the lowest numbered UART.
 */

/* First pick the console and ttys0.  This could be any of UART0-5 */

#if defined(CONFIG_UART0_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart0port	/* UART0 is console */
#define TTYS0_DEV           g_uart0port	/* UART0 is ttyS0 */
#define UART0_ASSIGNED      1
#elif defined(CONFIG_UART1_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart1port	/* UART1 is console */
#define TTYS0_DEV           g_uart1port	/* UART1 is ttyS0 */
#define UART1_ASSIGNED      1
#elif defined(CONFIG_UART2_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart2port	/* UART2 is console */
#define TTYS0_DEV           g_uart2port	/* UART2 is ttyS0 */
#define UART2_ASSIGNED      1
#elif defined(CONFIG_UART3_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart3port	/* UART3 is console */
#define TTYS0_DEV           g_uart3port	/* UART3 is ttyS0 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_UART4_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart4port	/* UART4 is console */
#define TTYS0_DEV           g_uart4port	/* UART4 is ttyS0 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_UART5_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart5port	/* UART5 is console */
#define TTYS5_DEV           g_uart5port	/* UART5 is ttyS0 */
#elif defined(CONFIG_UART6_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart6port	/* UART6 is console */
#define TTYS5_DEV           g_uart6port	/* UART6 is ttyS0 */
#elif defined(CONFIG_UART7_SERIAL_CONSOLE)
#define CONSOLE_DEV         g_uart7port	/* UART7 is console */
#define TTYS5_DEV           g_uart7port	/* UART7 is ttyS0 */
#else
#undef CONSOLE_DEV				/* No console */
#if defined(CONFIG_TIVA_UART0)
#define TTYS0_DEV           g_uart0port	/* UART0 is ttyS0 */
#define UART0_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART1)
#define TTYS0_DEV           g_uart1port	/* UART1 is ttyS0 */
#define UART1_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART2)
#define TTYS0_DEV           g_uart2port	/* UART2 is ttyS0 */
#define UART2_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART3)
#define TTYS0_DEV           g_uart3port	/* UART3 is ttyS0 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART4)
#define TTYS0_DEV           g_uart4port	/* UART4 is ttyS0 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5)
#define TTYS0_DEV           g_uart5port	/* UART5 is ttyS0 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6)
#define TTYS0_DEV           g_uart6port	/* UART5 is ttyS0 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7)
#define TTYS0_DEV           g_uart7port	/* UART5 is ttyS0 */
#define UART7_ASSIGNED      1
#endif
#endif

/* Pick ttys1.  This could be any of UART0-7 excluding the console UART. */

#if defined(CONFIG_TIVA_UART0) && !defined(UART0_ASSIGNED)
#define TTYS1_DEV           g_uart0port	/* UART0 is ttyS1 */
#define UART0_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART1) && !defined(UART1_ASSIGNED)
#define TTYS1_DEV           g_uart1port	/* UART1 is ttyS1 */
#define UART1_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART2) && !defined(UART2_ASSIGNED)
#define TTYS1_DEV           g_uart2port	/* UART2 is ttyS1 */
#define UART2_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART3) && !defined(UART3_ASSIGNED)
#define TTYS1_DEV           g_uart3port	/* UART3 is ttyS1 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART4) && !defined(UART4_ASSIGNED)
#define TTYS1_DEV           g_uart4port	/* UART4 is ttyS1 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS1_DEV           g_uart5port	/* UART5 is ttyS1 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS1_DEV           g_uart6port	/* UART6 is ttyS1 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS1_DEV           g_uart7port	/* UART7 is ttyS1 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys2.  This could be one of UART1-7. It can't be UART0 because that
 * was either assigned as ttyS0 or ttys1.  One of UART 1-7 could also be the
 * console.
 */

#if defined(CONFIG_TIVA_UART1) && !defined(UART1_ASSIGNED)
#define TTYS2_DEV           g_uart1port	/* UART1 is ttyS2 */
#define UART1_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART2) && !defined(UART2_ASSIGNED)
#define TTYS2_DEV           g_uart2port	/* UART2 is ttyS2 */
#define UART2_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART3) && !defined(UART3_ASSIGNED)
#define TTYS2_DEV           g_uart3port	/* UART3 is ttyS2 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART4) && !defined(UART4_ASSIGNED)
#define TTYS2_DEV           g_uart4port	/* UART4 is ttyS2 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS2_DEV           g_uart5port	/* UART5 is ttyS2 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS2_DEV           g_uart6port	/* UART6 is ttyS2 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS2_DEV           g_uart7port	/* UART7 is ttyS2 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys3. This could be one of UART2-7. It can't be UART0-1 because
 * those have already been assigned to ttsyS0, 1, or 2.  One of
 * UART 2-7 could also be the console.
 */

#if defined(CONFIG_TIVA_UART2) && !defined(UART2_ASSIGNED)
#define TTYS3_DEV           g_uart2port	/* UART2 is ttyS3 */
#define UART2_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART3) && !defined(UART3_ASSIGNED)
#define TTYS3_DEV           g_uart3port	/* UART3 is ttyS3 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART4) && !defined(UART4_ASSIGNED)
#define TTYS3_DEV           g_uart4port	/* UART4 is ttyS3 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS3_DEV           g_uart5port	/* UART5 is ttyS3 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS3_DEV           g_uart6port	/* UART6 is ttyS3 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS3_DEV           g_uart7port	/* UART7 is ttyS3 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys4. This could be one of UART3-7. It can't be UART0-2 because
 * those have already been assigned to ttsyS0, 1, 2 or 3.  One of
 * UART 3-7 could also be the console.
 */

#if defined(CONFIG_TIVA_UART3) && !defined(UART3_ASSIGNED)
#define TTYS4_DEV           g_uart3port	/* UART3 is ttyS4 */
#define UART3_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART4) && !defined(UART4_ASSIGNED)
#define TTYS4_DEV           g_uart4port	/* UART4 is ttyS4 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS4_DEV           g_uart5port	/* UART5 is ttyS4 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS4_DEV           g_uart6port	/* UART6 is ttyS4 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS4_DEV           g_uart7port	/* UART7 is ttyS4 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys5. This could be one of UART4-7. It can't be UART0-3 because
 * those have already been assigned to ttsyS0, 1, 2, 3 or 4.  One of
 * UART 4-7 could also be the console.
 */

#if defined(CONFIG_TIVA_UART4) && !defined(UART4_ASSIGNED)
#define TTYS5_DEV           g_uart4port	/* UART4 is ttyS5 */
#define UART4_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS5_DEV           g_uart5port	/* UART5 is ttyS5 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS5_DEV           g_uart6port	/* UART6 is ttyS5 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS5_DEV           g_uart7port	/* UART7 is ttyS5 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys6. This could be one of UART5-7. It can't be UART0-4 because
 * those have already been assigned to ttsyS0, 1, 2, 3, 4, or 5.  One of
 * UART 5-7 could also be the console.
 */

#if defined(CONFIG_TIVA_UART5) && !defined(UART5_ASSIGNED)
#define TTYS6_DEV           g_uart5port	/* UART5 is ttyS6 */
#define UART5_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS6_DEV           g_uart6port	/* UART6 is ttyS6 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS6_DEV           g_uart7port	/* UART7 is ttyS6 */
#define UART7_ASSIGNED      1
#endif

/* Pick ttys7. This could be one of UART6-7. It can't be UART0-5 because
 * those have already been assigned to ttsyS0, 1, 2, 3, 4, or 6.  One of
 * UART 6-7 could also be the console.
 */

#if defined(CONFIG_TIVA_UART6) && !defined(UART6_ASSIGNED)
#define TTYS7_DEV           g_uart6port	/* UART6 is ttyS7 */
#define UART6_ASSIGNED      1
#elif defined(CONFIG_TIVA_UART7) && !defined(UART7_ASSIGNED)
#define TTYS7_DEV           g_uart7port	/* UART7 is ttyS7 */
#define UART7_ASSIGNED      1
#endif

/****************************************************************************
 * Private Types
 ****************************************************************************/

struct up_dev_s {
	uint32_t uartbase;			/* Base address of UART registers */
	uint32_t baud;				/* Configured baud */
	uint32_t im;				/* Saved IM value */
	uint8_t irq;				/* IRQ associated with this UART */
	uint8_t parity;				/* 0=none, 1=odd, 2=even */
	uint8_t bits;				/* Number of bits (7 or 8) */
	bool stopbits2;				/* true: Configure with 2 stop bits instead of 1 */
};

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static int up_setup(struct uart_dev_s *dev);
static void up_shutdown(struct uart_dev_s *dev);
static int up_attach(struct uart_dev_s *dev);
static void up_detach(struct uart_dev_s *dev);
static int up_interrupt(int irq, void *context, FAR void *arg);
static int up_ioctl(FAR struct uart_dev_s *dev, int cmd, unsigned long arg);
static int up_receive(struct uart_dev_s *dev, uint32_t *status);
static void up_rxint(struct uart_dev_s *dev, bool enable);
static bool up_rxavailable(struct uart_dev_s *dev);
static void up_send(struct uart_dev_s *dev, int ch);
static void up_txint(struct uart_dev_s *dev, bool enable);
static bool up_txready(struct uart_dev_s *dev);
static bool up_txempty(struct uart_dev_s *dev);

/****************************************************************************
 * Private Variables
 ****************************************************************************/

static const struct uart_ops_s g_uart_ops = {
	.setup = up_setup,
	.shutdown = up_shutdown,
	.attach = up_attach,
	.detach = up_detach,
	.ioctl = up_ioctl,
	.receive = up_receive,
	.rxint = up_rxint,
	.rxavailable = up_rxavailable,
#ifdef CONFIG_SERIAL_IFLOWCONTROL
	.rxflowcontrol = NULL,
#endif
	.send = up_send,
	.txint = up_txint,
	.txready = up_txready,
	.txempty = up_txempty,
};

/* I/O buffers */

#ifdef CONFIG_TIVA_UART0
static char g_uart0rxbuffer[CONFIG_UART0_RXBUFSIZE];
static char g_uart0txbuffer[CONFIG_UART0_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART1
static char g_uart1rxbuffer[CONFIG_UART1_RXBUFSIZE];
static char g_uart1txbuffer[CONFIG_UART1_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART2
static char g_uart2rxbuffer[CONFIG_UART2_RXBUFSIZE];
static char g_uart2txbuffer[CONFIG_UART2_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART3
static char g_uart3rxbuffer[CONFIG_UART3_RXBUFSIZE];
static char g_uart3txbuffer[CONFIG_UART3_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART4
static char g_uart4rxbuffer[CONFIG_UART4_RXBUFSIZE];
static char g_uart4txbuffer[CONFIG_UART4_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART5
static char g_uart5rxbuffer[CONFIG_UART5_RXBUFSIZE];
static char g_uart5txbuffer[CONFIG_UART5_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART6
static char g_uart6rxbuffer[CONFIG_UART6_RXBUFSIZE];
static char g_uart6txbuffer[CONFIG_UART6_TXBUFSIZE];
#endif
#ifdef CONFIG_TIVA_UART7
static char g_uart7rxbuffer[CONFIG_UART7_RXBUFSIZE];
static char g_uart7txbuffer[CONFIG_UART7_TXBUFSIZE];
#endif

/* This describes the state of the Stellaris uart0 port. */

#ifdef CONFIG_TIVA_UART0
static struct up_dev_s g_uart0priv = {
	.uartbase = TIVA_UART0_BASE,
	.baud = CONFIG_UART0_BAUD,
	.irq = TIVA_IRQ_UART0,
	.parity = CONFIG_UART0_PARITY,
	.bits = CONFIG_UART0_BITS,
	.stopbits2 = CONFIG_UART0_2STOP,
};

static uart_dev_t g_uart0port = {
	.recv = {
		.size = CONFIG_UART0_RXBUFSIZE,
		.buffer = g_uart0rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART0_TXBUFSIZE,
		.buffer = g_uart0txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart0priv,
};
#endif

/* This describes the state of the Stellaris uart1 port. */

#ifdef CONFIG_TIVA_UART1
static struct up_dev_s g_uart1priv = {
	.uartbase = TIVA_UART1_BASE,
	.baud = CONFIG_UART1_BAUD,
	.irq = TIVA_IRQ_UART1,
	.parity = CONFIG_UART1_PARITY,
	.bits = CONFIG_UART1_BITS,
	.stopbits2 = CONFIG_UART1_2STOP,
};

static uart_dev_t g_uart1port = {
	.recv = {
		.size = CONFIG_UART1_RXBUFSIZE,
		.buffer = g_uart1rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART1_TXBUFSIZE,
		.buffer = g_uart1txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart1priv,
};
#endif

/* This describes the state of the Stellaris uart2 port. */

#ifdef CONFIG_TIVA_UART2
static struct up_dev_s g_uart2priv = {
	.uartbase = TIVA_UART2_BASE,
	.baud = CONFIG_UART2_BAUD,
	.irq = TIVA_IRQ_UART2,
	.parity = CONFIG_UART2_PARITY,
	.bits = CONFIG_UART2_BITS,
	.stopbits2 = CONFIG_UART2_2STOP,
};

static uart_dev_t g_uart2port = {
	.recv = {
		.size = CONFIG_UART2_RXBUFSIZE,
		.buffer = g_uart2rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART2_TXBUFSIZE,
		.buffer = g_uart2txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart2priv,
};
#endif

/* This describes the state of the Stellaris uart3 port. */

#ifdef CONFIG_TIVA_UART3
static struct up_dev_s g_uart3priv = {
	.uartbase = TIVA_UART3_BASE,
	.baud = CONFIG_UART3_BAUD,
	.irq = TIVA_IRQ_UART3,
	.parity = CONFIG_UART3_PARITY,
	.bits = CONFIG_UART3_BITS,
	.stopbits2 = CONFIG_UART3_2STOP,
};

static uart_dev_t g_uart3port = {
	.recv = {
		.size = CONFIG_UART3_RXBUFSIZE,
		.buffer = g_uart3rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART3_TXBUFSIZE,
		.buffer = g_uart3txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart3priv,
};
#endif

/* This describes the state of the Stellaris uart4 port. */

#ifdef CONFIG_TIVA_UART4
static struct up_dev_s g_uart4priv = {
	.uartbase = TIVA_UART4_BASE,
	.baud = CONFIG_UART4_BAUD,
	.irq = TIVA_IRQ_UART4,
	.parity = CONFIG_UART4_PARITY,
	.bits = CONFIG_UART4_BITS,
	.stopbits2 = CONFIG_UART4_2STOP,
};

static uart_dev_t g_uart4port = {
	.recv = {
		.size = CONFIG_UART4_RXBUFSIZE,
		.buffer = g_uart4rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART4_TXBUFSIZE,
		.buffer = g_uart4txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart4priv,
};
#endif

/* This describes the state of the Stellaris uart5 port. */

#ifdef CONFIG_TIVA_UART5
static struct up_dev_s g_uart5priv = {
	.uartbase = TIVA_UART5_BASE,
	.baud = CONFIG_UART5_BAUD,
	.irq = TIVA_IRQ_UART5,
	.parity = CONFIG_UART5_PARITY,
	.bits = CONFIG_UART5_BITS,
	.stopbits2 = CONFIG_UART5_2STOP,
};

static uart_dev_t g_uart5port = {
	.recv = {
		.size = CONFIG_UART5_RXBUFSIZE,
		.buffer = g_uart5rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART5_TXBUFSIZE,
		.buffer = g_uart5txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart5priv,
};
#endif

/* This describes the state of the Stellaris uart6 port. */

#ifdef CONFIG_TIVA_UART6
static struct up_dev_s g_uart6priv = {
	.uartbase = TIVA_UART6_BASE,
	.baud = CONFIG_UART6_BAUD,
	.irq = TIVA_IRQ_UART6,
	.parity = CONFIG_UART6_PARITY,
	.bits = CONFIG_UART6_BITS,
	.stopbits2 = CONFIG_UART6_2STOP,
};

static uart_dev_t g_uart6port = {
	.recv = {
		.size = CONFIG_UART6_RXBUFSIZE,
		.buffer = g_uart6rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART6_TXBUFSIZE,
		.buffer = g_uart6txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart6priv,
};
#endif

/* This describes the state of the Stellaris uart7 port. */

#ifdef CONFIG_TIVA_UART7
static struct up_dev_s g_uart7priv = {
	.uartbase = TIVA_UART7_BASE,
	.baud = CONFIG_UART7_BAUD,
	.irq = TIVA_IRQ_UART7,
	.parity = CONFIG_UART7_PARITY,
	.bits = CONFIG_UART7_BITS,
	.stopbits2 = CONFIG_UART7_2STOP,
};

static uart_dev_t g_uart7port = {
	.recv = {
		.size = CONFIG_UART7_RXBUFSIZE,
		.buffer = g_uart7rxbuffer,
	},
	.xmit = {
		.size = CONFIG_UART7_TXBUFSIZE,
		.buffer = g_uart7txbuffer,
	},
	.ops = &g_uart_ops,
	.priv = &g_uart7priv,
};
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_serialin
 ****************************************************************************/

static inline uint32_t up_serialin(struct up_dev_s *priv, int offset)
{
	return getreg32(priv->uartbase + offset);
}

/****************************************************************************
 * Name: up_serialout
 ****************************************************************************/

static inline void up_serialout(struct up_dev_s *priv, int offset, uint32_t value)
{
	putreg32(value, priv->uartbase + offset);
}

/****************************************************************************
 * Name: up_disableuartint
 ****************************************************************************/

static inline void up_disableuartint(struct up_dev_s *priv, uint32_t *im)
{
	/* Return the current interrupt mask value */

	if (im) {
		*im = priv->im;
	}

	/* Disable all interrupts */

	priv->im = 0;
	up_serialout(priv, TIVA_UART_IM_OFFSET, 0);
}

/****************************************************************************
 * Name: up_restoreuartint
 ****************************************************************************/

static inline void up_restoreuartint(struct up_dev_s *priv, uint32_t im)
{
	priv->im = im;
	up_serialout(priv, TIVA_UART_IM_OFFSET, im);
}

/****************************************************************************
 * Name: up_waittxnotfull
 ****************************************************************************/

#ifdef HAVE_SERIAL_CONSOLE
static inline void up_waittxnotfull(struct up_dev_s *priv)
{
	volatile int tmp;

	/* Limit how long we will wait for the TX available condition */

	for (tmp = 1000; tmp > 0; tmp--) {
		/* Check Tx FIFO is full */

		if ((up_serialin(priv, TIVA_UART_FR_OFFSET) & UART_FR_TXFF) == 0) {
			/* The Tx FIFO is not full... return */

			break;
		}
	}

	/* If we get here, then the wait has timed out and the Tx FIFO remains
	 * full.
	 */
}
#endif

/****************************************************************************
 * Name: up_setup
 *
 * Description:
 *   Configure the UART baud, bits, parity, fifos, etc. This
 *   method is called the first time that the serial port is
 *   opened.
 *
 ****************************************************************************/

static int up_setup(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	uint32_t lcrh;
	uint32_t ctl;
#ifndef CONFIG_SUPPRESS_UART_CONFIG
	uint32_t den;
	uint32_t brdi;
	uint32_t remainder;
	uint32_t divfrac;

	/* Note:  The logic here depends on the fact that that the UART module
	 * was enabled and the GPIOs were configured in up_lowsetup().
	 */

	/* Disable the UART by clearing the UARTEN bit in the UART CTL register */

	ctl = up_serialin(priv, TIVA_UART_CTL_OFFSET);
	ctl &= ~UART_CTL_UARTEN;
	up_serialout(priv, TIVA_UART_CTL_OFFSET, ctl);

	/* Calculate BAUD rate from the SYS clock:
	 *
	 * "The baud-rate divisor is a 22-bit number consisting of a 16-bit integer
	 *  and a 6-bit fractional part. The number formed by these two values is
	 *  used by the baud-rate generator to determine the bit period. Having a
	 *  fractional baud-rate divider allows the UART to generate all the standard
	 *  baud rates.
	 *
	 * "The 16-bit integer is loaded through the UART Integer Baud-Rate Divisor
	 *  (UARTIBRD) register ... and the 6-bit fractional part is loaded with the
	 *  UART Fractional Baud-Rate Divisor (UARTFBRD) register... The baud-rate
	 *  divisor (BRD) has the following relationship to the system clock (where
	 *  BRDI is the integer part of the BRD and BRDF is the fractional part,
	 *  separated by a decimal place.):
	 *
	 *    "BRD = BRDI + BRDF = UARTSysClk / (16 * Baud Rate)
	 *
	 * "where UARTSysClk is the system clock connected to the UART. The 6-bit
	 *  fractional number (that is to be loaded into the DIVFRAC bit field in the
	 *  UARTFBRD register) can be calculated by taking the fractional part of the
	 *  baud-rate divisor, multiplying it by 64, and adding 0.5 to account for
	 *  rounding errors:
	 *
	 *    "UARTFBRD[DIVFRAC] = integer(BRDF * 64 + 0.5)
	 *
	 * "The UART generates an internal baud-rate reference clock at 16x the baud-
	 *  rate (referred to as Baud16). This reference clock is divided by 16 to
	 *  generate the transmit clock, and is used for error detection during receive
	 *  operations.
	 *
	 * "Along with the UART Line Control, High Byte (UARTLCRH) register ..., the
	 *  UARTIBRD and UARTFBRD registers form an internal 30-bit register. This
	 *  internal register is only updated when a write operation to UARTLCRH is
	 *  performed, so any changes to the baud-rate divisor must be followed by a
	 *  write to the UARTLCRH register for the changes to take effect. ..."
	 */

	den = priv->baud << 4;
	brdi = SYSCLK_FREQUENCY / den;
	remainder = SYSCLK_FREQUENCY - den * brdi;
	divfrac = ((remainder << 6) + (den >> 1)) / den;

	up_serialout(priv, TIVA_UART_IBRD_OFFSET, brdi);
	up_serialout(priv, TIVA_UART_FBRD_OFFSET, divfrac);

	/* Set up the LCRH register */

	lcrh = 0;
	switch (priv->bits) {
	case 5:
		lcrh |= UART_LCRH_WLEN_5BITS;
		break;
	case 6:
		lcrh |= UART_LCRH_WLEN_6BITS;
		break;
	case 7:
		lcrh |= UART_LCRH_WLEN_7BITS;
		break;
	case 8:
	default:
		lcrh |= UART_LCRH_WLEN_8BITS;
		break;
	}

	switch (priv->parity) {
	case 0:
	default:
		break;
	case 1:
		lcrh |= UART_LCRH_PEN;
		break;
	case 2:
		lcrh |= UART_LCRH_PEN | UART_LCRH_EPS;
		break;
	}

	if (priv->stopbits2) {
		lcrh |= UART_LCRH_STP2;
	}

	up_serialout(priv, TIVA_UART_LCRH_OFFSET, lcrh);
#endif

	/* Set the UART to interrupt whenever the TX FIFO is almost empty or when
	 * any character is received.
	 */

	up_serialout(priv, TIVA_UART_IFLS_OFFSET, UART_IFLS_TXIFLSEL_18th | UART_IFLS_RXIFLSEL_18th);

	/* Flush the Rx and Tx FIFOs -- How do you do that? */

	/* Enable Rx interrupts from the UART except for Tx interrupts.  We don't want
	 * Tx interrupts until we have something to send.  We will check for serial
	 * errors as part of Rx interrupt processing (no interrupts will be received
	 * yet because the interrupt is still disabled at the interrupt controller.
	 */

	up_serialout(priv, TIVA_UART_IM_OFFSET, UART_IM_RXIM | UART_IM_RTIM);

	/* Enable the FIFOs */

#ifdef CONFIG_SUPPRESS_UART_CONFIG
	lcrh = up_serialin(priv, TIVA_UART_LCRH_OFFSET);
#endif
	lcrh |= UART_LCRH_FEN;
	up_serialout(priv, TIVA_UART_LCRH_OFFSET, lcrh);

	/* Enable Rx, Tx, and the UART */

#ifdef CONFIG_SUPPRESS_UART_CONFIG
	ctl = up_serialin(priv, TIVA_UART_CTL_OFFSET);
#endif
	ctl |= (UART_CTL_UARTEN | UART_CTL_TXE | UART_CTL_RXE);
	up_serialout(priv, TIVA_UART_CTL_OFFSET, ctl);

	/* Set up the cache IM value */

	priv->im = up_serialin(priv, TIVA_UART_IM_OFFSET);
	return OK;
}

/****************************************************************************
 * Name: up_shutdown
 *
 * Description:
 *   Disable the UART.  This method is called when the serial
 *   port is closed
 *
 ****************************************************************************/

static void up_shutdown(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	up_disableuartint(priv, NULL);
}

/****************************************************************************
 * Name: up_attach
 *
 * Description:
 *   Configure the UART to operation in interrupt driven mode.  This method is
 *   called when the serial port is opened.  Normally, this is just after the
 *   the setup() method is called, however, the serial console may operate in
 *   a non-interrupt driven mode during the boot phase.
 *
 *   RX and TX interrupts are not enabled when by the attach method (unless the
 *   hardware supports multiple levels of interrupt enabling).  The RX and TX
 *   interrupts are not enabled until the txint() and rxint() methods are called.
 *
 ****************************************************************************/

static int up_attach(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	int ret;

	/* Attach and enable the IRQ */

	ret = irq_attach(priv->irq, up_interrupt, NULL);
	if (ret == OK) {
		/* Enable the interrupt (RX and TX interrupts are still disabled
		 * in the UART
		 */

		up_enable_irq(priv->irq);
	}
	return ret;
}

/****************************************************************************
 * Name: up_detach
 *
 * Description:
 *   Detach UART interrupts.  This method is called when the serial port is
 *   closed normally just before the shutdown method is called.  The exception is
 *   the serial console which is never shutdown.
 *
 ****************************************************************************/

static void up_detach(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	up_disable_irq(priv->irq);
	irq_detach(priv->irq);
}

/****************************************************************************
 * Name: up_interrupt
 *
 * Description:
 *   This is the UART interrupt handler.  It will be invoked
 *   when an interrupt received on the 'irq'  It should call
 *   uart_transmitchars or uart_receivechar to perform the
 *   appropriate data transfers.  The interrupt handling logic\
 *   must be able to map the 'irq' number into the approprite
 *   uart_dev_s structure in order to call these functions.
 *
 ****************************************************************************/

static int up_interrupt(int irq, void *context, FAR void *arg)
{
	struct uart_dev_s *dev = NULL;
	struct up_dev_s *priv;
	uint32_t mis;
	int passes;
	bool handled;

#ifdef CONFIG_TIVA_UART0
	if (g_uart0priv.irq == irq) {
		dev = &g_uart0port;
	} else
#endif
#ifdef CONFIG_TIVA_UART1
		if (g_uart1priv.irq == irq) {
			dev = &g_uart1port;
		} else
#endif
#ifdef CONFIG_TIVA_UART2
			if (g_uart2priv.irq == irq) {
				dev = &g_uart2port;
			} else
#endif
#ifdef CONFIG_TIVA_UART3
				if (g_uart3priv.irq == irq) {
					dev = &g_uart3port;
				} else
#endif
#ifdef CONFIG_TIVA_UART4
					if (g_uart4priv.irq == irq) {
						dev = &g_uart4port;
					} else
#endif
#ifdef CONFIG_TIVA_UART5
						if (g_uart5priv.irq == irq) {
							dev = &g_uart5port;
						} else
#endif
#ifdef CONFIG_TIVA_UART6
							if (g_uart6priv.irq == irq) {
								dev = &g_uart6port;
							} else
#endif
#ifdef CONFIG_TIVA_UART7
								if (g_uart7priv.irq == irq) {
									dev = &g_uart7port;
								} else
#endif
								{
									PANIC();
								}

	priv = (struct up_dev_s *)dev->priv;

	/* Loop until there are no characters to be transferred or,
	 * until we have been looping for a long time.
	 */

	handled = true;
	for (passes = 0; passes < 256 && handled; passes++) {
		handled = false;

		/* Get the masked UART status and clear the pending interrupts. */

		mis = up_serialin(priv, TIVA_UART_MIS_OFFSET);
		up_serialout(priv, TIVA_UART_ICR_OFFSET, mis);

		/* Handle incoming, receive bytes (with or without timeout) */

		if ((mis & (UART_MIS_RXMIS | UART_MIS_RTMIS)) != 0) {
			/* Rx buffer not empty ... process incoming bytes */

			uart_recvchars(dev);
			handled = true;
		}

		/* Handle outgoing, transmit bytes */

		if ((mis & UART_MIS_TXMIS) != 0) {
			/* Tx FIFO not full ... process outgoing bytes */

			uart_xmitchars(dev);
			handled = true;
		}
	}
	return OK;
}

/****************************************************************************
 * Name: up_ioctl
 *
 * Description:
 *   All ioctl calls will be routed through this method
 *
 ****************************************************************************/

static int up_ioctl(FAR struct uart_dev_s *dev, int cmd, unsigned long arg)
{
	int ret = OK;

	switch (cmd) {
#ifdef CONFIG_SERIAL_TIOCSERGSTRUCT
	case TIOCSERGSTRUCT: {
		struct up_dev_s *user = (struct up_dev_s *)arg;
		if (!user) {
			ret = -EINVAL;
		} else {
			memcpy(user, dev, sizeof(struct up_dev_s));
		}
	}
	break;
#endif

	default:
		ret = -ENOTTY;
		break;
	}

	return ret;
}

/****************************************************************************
 * Name: up_receive
 *
 * Description:
 *   Called (usually) from the interrupt level to receive one
 *   character from the UART.  Error bits associated with the
 *   receipt are provided in the return 'status'.
 *
 ****************************************************************************/

static int up_receive(struct uart_dev_s *dev, uint32_t *status)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	uint32_t rxd;

	/* Get the Rx byte + 4 bits of error information.  Return those in status */

	rxd = up_serialin(priv, TIVA_UART_DR_OFFSET);
	*status = rxd;

	/* The lower 8bits of the Rx data is the actual recevied byte */

	return rxd & 0xff;
}

/****************************************************************************
 * Name: up_rxint
 *
 * Description:
 *   Call to enable or disable RX interrupts
 *
 ****************************************************************************/

static void up_rxint(struct uart_dev_s *dev, bool enable)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	if (enable) {
		/* Receive an interrupt when their is anything in the Rx FIFO (or an Rx
		 * timeout occurs.
		 */

#ifndef CONFIG_SUPPRESS_SERIAL_INTS
		priv->im |= (UART_IM_RXIM | UART_IM_RTIM);
#endif
	} else {
		priv->im &= ~(UART_IM_RXIM | UART_IM_RTIM);
	}
	up_serialout(priv, TIVA_UART_IM_OFFSET, priv->im);
}

/****************************************************************************
 * Name: up_rxavailable
 *
 * Description:
 *   Return true if the receive fifo is not empty
 *
 ****************************************************************************/

static bool up_rxavailable(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	return ((up_serialin(priv, TIVA_UART_FR_OFFSET) & UART_FR_RXFE) == 0);
}

/****************************************************************************
 * Name: up_send
 *
 * Description:
 *   This method will send one byte on the UART
 *
 ****************************************************************************/

static void up_send(struct uart_dev_s *dev, int ch)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	up_serialout(priv, TIVA_UART_DR_OFFSET, (uint32_t) ch);
}

/****************************************************************************
 * Name: up_txint
 *
 * Description:
 *   Call to enable or disable TX interrupts
 *
 ****************************************************************************/

static void up_txint(struct uart_dev_s *dev, bool enable)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	irqstate_t flags;

	flags = irqsave();
	if (enable) {
		/* Set to receive an interrupt when the TX fifo is half emptied */

#ifndef CONFIG_SUPPRESS_SERIAL_INTS
		priv->im |= UART_IM_TXIM;
		up_serialout(priv, TIVA_UART_IM_OFFSET, priv->im);

		/* The serial driver wants an interrupt here, but will not get get
		 * one unless we "prime the pump."  I believe that this is because
		 * behave like a level interrupt and the Stellaris interrupts behave
		 * (at least by default) like edge interrupts.
		 *
		 * In any event, faking a TX interrupt here solves the problem;
		 * Call uart_xmitchars() just as would have been done if we received
		 * the TX interrupt.
		 */

		uart_xmitchars(dev);
#endif
	} else {
		/* Disable the TX interrupt */

		priv->im &= ~UART_IM_TXIM;
		up_serialout(priv, TIVA_UART_IM_OFFSET, priv->im);
	}
	irqrestore(flags);
}

/****************************************************************************
 * Name: up_txready
 *
 * Description:
 *   Return true if the tranmsit fifo is not full
 *
 ****************************************************************************/

static bool up_txready(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	return ((up_serialin(priv, TIVA_UART_FR_OFFSET) & UART_FR_TXFF) == 0);
}

/****************************************************************************
 * Name: up_txempty
 *
 * Description:
 *   Return true if the transmit fifo is empty
 *
 ****************************************************************************/

static bool up_txempty(struct uart_dev_s *dev)
{
	struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
	return ((up_serialin(priv, TIVA_UART_FR_OFFSET) & UART_FR_TXFE) != 0);
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_serialinit
 *
 * Description:
 *   Performs the low level UART initialization early in
 *   debug so that the serial console will be available
 *   during bootup.  This must be called before up_serialinit.
 *
 ****************************************************************************/

void up_earlyserialinit(void)
{
	/* NOTE:  All GPIO configuration for the UARTs was performed in
	 * up_lowsetup
	 */

	/* Disable all UARTS */

	up_disableuartint(TTYS0_DEV.priv, NULL);
#ifdef TTYS1_DEV
	up_disableuartint(TTYS1_DEV.priv, NULL);
#endif
#ifdef TTYS2_DEV
	up_disableuartint(TTYS2_DEV.priv, NULL);
#endif
#ifdef TTYS3_DEV
	up_disableuartint(TTYS3_DEV.priv, NULL);
#endif
#ifdef TTYS4_DEV
	up_disableuartint(TTYS4_DEV.priv, NULL);
#endif
#ifdef TTYS5_DEV
	up_disableuartint(TTYS5_DEV.priv, NULL);
#endif
#ifdef TTYS6_DEV
	up_disableuartint(TTYS6_DEV.priv, NULL);
#endif
#ifdef TTYS7_DEV
	up_disableuartint(TTYS7_DEV.priv, NULL);
#endif

	/* Configure whichever one is the console */

#ifdef HAVE_SERIAL_CONSOLE
	CONSOLE_DEV.isconsole = true;
	up_setup(&CONSOLE_DEV);
#endif
}

/****************************************************************************
 * Name: up_serialinit
 *
 * Description:
 *   Register serial console and serial ports.  This assumes
 *   that up_earlyserialinit was called previously.
 *
 ****************************************************************************/

void up_serialinit(void)
{
	/* Register the console */

#ifdef HAVE_SERIAL_CONSOLE
	(void)uart_register("/dev/console", &CONSOLE_DEV);
#endif

	/* Register all UARTs */

	(void)uart_register("/dev/ttyS0", &TTYS0_DEV);
#ifdef TTYS1_DEV
	(void)uart_register("/dev/ttyS1", &TTYS1_DEV);
#endif
#ifdef TTYS2_DEV
	(void)uart_register("/dev/ttyS2", &TTYS2_DEV);
#endif
#ifdef TTYS3_DEV
	(void)uart_register("/dev/ttyS3", &TTYS3_DEV);
#endif
#ifdef TTYS4_DEV
	(void)uart_register("/dev/ttyS4", &TTYS4_DEV);
#endif
#ifdef TTYS5_DEV
	(void)uart_register("/dev/ttyS5", &TTYS5_DEV);
#endif
#ifdef TTYS6_DEV
	(void)uart_register("/dev/ttyS6", &TTYS6_DEV);
#endif
#ifdef TTYS7_DEV
	(void)uart_register("/dev/ttyS7", &TTYS7_DEV);
#endif
}

/****************************************************************************
 * Name: up_putc
 *
 * Description:
 *   Provide priority, low-level access to support OS debug  writes
 *
 ****************************************************************************/

int up_putc(int ch)
{
#ifdef HAVE_SERIAL_CONSOLE
	struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
	uint32_t im;

	up_disableuartint(priv, &im);

	/* Check for LF */

	if (ch == '\n') {
		/* Add CR */

		up_waittxnotfull(priv);
		up_serialout(priv, TIVA_UART_DR_OFFSET, (uint32_t) '\r');
	}

	up_waittxnotfull(priv);
	up_serialout(priv, TIVA_UART_DR_OFFSET, (uint32_t) ch);

	up_waittxnotfull(priv);
	up_restoreuartint(priv, im);
#endif
	return ch;
}

#else							/* USE_SERIALDRIVER */

/****************************************************************************
 * Name: up_putc
 *
 * Description:
 *   Provide priority, low-level access to support OS debug writes
 *
 ****************************************************************************/

int up_putc(int ch)
{
#ifdef HAVE_SERIAL_CONSOLE
	/* Check for LF */

	if (ch == '\n') {
		/* Add CR */

		up_lowputc('\r');
	}

	up_lowputc(ch);
#endif
	return ch;
}

#endif							/* USE_SERIALDRIVER */
